Screen flickering of Hp laptop

[Susan]

My friend’s laptop for some reason whenever its battery is connected it starts to flicker and it can even sometimes turn black for a small moment and using a laptop directly off the power source is no better than working it as a desktop. So what would be the issue causing this problem.

 

[walikirito]

The maximum chance is that the battery of your laptop is busted and its needs to be replaced.
If its flickering with low and high brightness then its most likely as such that the battery is connecting and disconnecting with the laptop and leading to the flickering of the screen.